Odograph



June 3, 1947.

FIG.'1.

C. D. LAKE El' AL ODOGRAPH Filed April 2, 1943 11 Sheets-Sheet l 21 ORNE Y June 3, 1947. C, D, LAKE Er AL 2,421,628

oDoGRAPH Filed April 2, 1945 11 Sheets-Sheet 2 zal I fg .INV N O S 3%@ ATTORNEY June 3, 1947. c. D. LAKE ET AL ODOGRAPH Filed April 2, 1943 11 Sheets-Sheet 3 NS ma www ATTORNEY June 3, 1947. c. o. LAKE Er AL ODOGRAPH Filed April 2, 1943 11 Sheets-Sheet 4 w A m5 June 3, 1947. C, D, LAKE Er AL 2,421,628

ODOGRAPH Filed April 2, 1943 l1 Sheets-Sheet 5 f gw BY VZ M2 M ATTORNEY June 3, 1947. C, D, LAKE ET AL 2,421,628

Flan.

n I'I lllllllllluHTl-:J-ll

A'TTORNEY June 3, 1947. Q D LAKE Er AL 2,421,628

ODOGRAPH Filed April 2, 1943 11 Sheets-Sheet 7 5 www, mgica? ma ATTORNEY `lune 3, 1947.

C.D.LAKE ETAL oDoGRAPH Filed April 2, 1943 Flc-5.45. i '@l l1 Sheets-Sheet 8 FIC-M4.

BY Whg/ June 3, 1947. c. D. LAKE Er AL ODOGRAPH Filed April 2, 1945 11 Sheets-Sheet 9 Fl GAS.

INVE O S #ATTORNEY June 3, 1947. c. n. LAKE ET AL.

ODOGRAPH 11 Sheets-sheet 1o Filed April 2, 1943 NWN mwN

June 3, 1947. C, D, LAKE ET AL 2,421,628

ODOGRAPH Filed April 2, 1943 ll She-ets-'Sheet l1 rroRNEY Patented June 3, 1947 ODOGRAPH Clair D. Lake, Binghamton, and George F. Daly, Endicott, N. Y., assgnors to International Business Machines Corporation, New York, N. Y., a corporation of New York Application April 2, 1943, Serial No. 481,546

This invention relates to apparatus for indicating and recording the course of a vehicle.

The principal object of the invention is to provide improvements in such apparatus to the end that its usefulness and reliability may be increased. In carrying out the objects of the invention, a table or carrier is provided which rcceives a map or paper (ruled or blank) and has a scriberl or stylus cooperating therewith for recording the location of the vehicle on the map or paper. The scriber is moved across the sur face of the map under control of an integrating mechanism of an improved form which receives the directional data from a compass and data respecting distance traveled from the driving means of the vehicle.

A particular object of the invention is to provide improved integrating mechanism for resolving the movement or course of the vehicle into cardinal components which includes a disk or wheel, which is rotated by pawl mechanism driven at a rate depending on the speed of the vehicle, the effective movements of the pawl mechanism depending on the magnitude of the particula-r component of the direction of movement, so that the movement registered is dependent on the component of the speed.

A further object of the invention resides in the provision of improved ratio connections between the integrating mechanism and the s criber, which has incorporated therein variably adjustable devices to accommodate a greater range of map scales than has heretofore been possible.

A still further object of the invention resides in the provision of improved mechanism for obtaining a reading of the directional compass position and adjusting the integrating mechanism accordingly, which includes devices for continuously hunting within a predetermined angular range to ascertain the compass needle position, such continuous hunting action to also be applied to the mechanism which controls the eilective movement of the integrating pawls to thereby produce an averaging eect, which is highly advantageous in contributing to the accuracy of the apparatus. v A still further object resides in the provision of improved mechanism for effecting an initial orientation of the apparatus to correct for the variation between true and magnetic north to the end that the vehicles course will be correctly plotted on maps prepared in accordance with true north indications.

Other objects of the invention will be pointed l out 1n the following description and claims and 11 Claims. -(Cl. Tir-125.5)

illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings:

Fig. 1 is a plan view of one end of the apparatus with parts at left broken away.

Fig. 2 is a plan View of the opposite end with parts at both sides removed, with Figs. 1 and 2 taken together constituting a plan view of the lower section of the devicewhen placed one above the other in the order named,

Fig, 3 is an end View of the device showing the map scale adjusting mechanism, the view looking in the direction of the lines 3-'3 in Fig. 2..

Fig. 4 is a section taken along lines 4--4 of Fig. 2, showing the interior of the map scale ratio adjusting devices.

Fig. 5 is a, longitudinal section of the parts shown in Fig. 2, substantially along the lines 5--5 of Fig. 2..

Fig. 6 is a sectional View taken along lines 6--6 of. Fig. 4.

Fig. 7 is a sectional view taken along lines 'l-l of Fig. 4.

Fig. 8 is a section taken along lines 8-8 of Fig. 6.

Fig. 9 is a detail showing the map scale dial, the view being taken along lines 9-9 of Fig. 2.

Fig. 10 is a sectional view taken substantially along lines llll0 of Fig. 2,

Fig. 11 is a sectional view taken substantially along lines H-II of Fig. 2.

Fig. 12 is a plan section taken along lines |2--l2 of Fig. 10,

Fig. 13 is a view showing certain of the parts of Fig. 12 in a. different position.

Fig. 14 is a transverse section taken substantially along the lines Ill-i4 of Fig. 1.

Fig. l5 is a sectional detail of the driving connections to the compass. 1

Fig. 16 is a sectional view taken along lines I6-l6 of Fig. 15.

Fig. 17 is a detail taken along the lines Il--II of Figi.

Fig. 18 is a detail of the counters, the view being taken substantially along lines Ill-I8 of Fig. l.

Fig. 19 is a detail showing the compass reading devices, their manner of connection to the integrating mechanism, and the clutch controlling circuit connections.

Fig. 20 is a detail of a. shutter mechanism, the section being substantially along lines 20--20 of Fig. 18.

Fig. 20a is a detail section along lines 20a-25a of Fig. 18.

Fig. 21 is a. sectional elevation of the scribing carriage and its operating mechanism.

Fis. 22 is a plan view of part of the map table showing the relationship therewith of the scriber or pencil carriage.

Fig. 23 is a detail taken along lines 23-23 of Fig. 22, showing the north-south lead screw and the manner of connecting the carriage thereto.

Fig. 24 is a detail section taken along line 24-24 of Fig. 22 showing the pencil holder and the manner of connecting the same to the east-west lead screw.

Figs. 1 and 2, when placed one above the other, provide a picture of the plan view oi' the mechanism beneath the map table. It shows the compass connection at the upper end with the counters or indicators, while Fig. 2 shows the location of the integrating mechanism in the upper part and the map scale ratio adjusting mechanism in the lower part of the ligure.

Drive mechanism-The motor Ill (Fig. 1) is provided and is constantly in operation through connection to a suitable source of current in the vehicle. The motor pinion drives the gear l2 integral with a pinion i3 which in turn drives a gear |4 secured to a cross-shaft I5. This shaft at its opposite end carries a gear I5 (see Fig. 17) which meshes with a clutch driving gear I1. At an intermediate point along shaft I5 is a gear I5 which drives an idler I9 which is in mesh with a clutch driving gear 25. Both clutch driving gears |1 and 20 are freely carried by a cross rod 2| and are constrained against axial movement on the rod, and through the gear connections just traced it will be observed that the gears I1 and 20 rotate constantly but in opposite direction. Intermediate the two gears and freely rotatable on shaft 2| is a pair of gears 22 slidable along the shaft into frictional engagement with either of the driving gears I1 or 2l, the faces of the latter being provided with suitable frictional material for driving action.

Bell crank yoke 23 pivoted at 24 (Fig. 1) may be rocked in one direction by a magnet 25 and in the opposite direction by a magnet 25. When the device is in operation, one or the other of the magnets will .be in operation, i. e., energized, so that there is driving connection between its related gear 22 and one of the driving gears |1 or 25. The gears 22 have connection with a pair of gears 21 secured on a cross rod 25, to one end of which is secured bevel pinion 29 which meshes with a bevel gear 35 on shaft 3|, with the result that shaft 3| is rotated in either direction depending .upon which of the two magnets is energized. As

will be presently pointed out, when the vehicle is traveling along a. straight line, the magnets 25 and 25 are alternately energized so that through the driving connections traced the shaft 3| receives an oscillatory motion, which is transmitted in one direction to the compass sensing devices and in the other direction to the integrating mechanism.

Compass sensing mechanism-Tracing first the connections to the compass, the shaft 3| carries the pinion I2 (see Figs. 15 and 16) which meshes with a differential pinion 33 which in turn drives pinion 34 to drive a pinion 35 on shaft 36. which is coaxial with the shaft 3|. During the operation of the device, the centers of the pinions 33 and 34 are stationary, so that shaft 3B is oscillated through the same angle as shaft 3| but in the opposite direction. The shaft 35 carries a bevel gear I1 meshing with bevel gear 35 secured to the end of a flexible shaft 35 which extends to the compass. In Fig. 19 is shown diagrammatically the controlling mechanism for the magnets 25 and 25.

Inasmuch as the particular form of compass and the reading means therefor form no part of the present invention, it is suiilcient to indicate simply the compass needle 45 upon which is secured a mirror 4|, so that the mirror rotates with the compass needle. In the plane of the mirror there are provided a pair of light responsive cells 42 and a light source 43. With the mirror in position to reflect light from source 43 to one of the cells, electronic control circuits (which per se are also no part of the present invention) amplify the current from the cell to cause energization of one of the magnets 25 or 25 and, when the mirror is in position to reflect light upon the other cell, the second magnet would be energized. The cells 42 and light source 43 are mounted upon a gear 45 meshing with a gear 45 which is carried by the end of the flexible shaft 35 which, as has been explained, is capable of rotation in either direction.

When the mechanism is started, the compass sensing assembLv comprising the cells and light source may be standing in any position, while the magnetic needle is directed toward the north pole and controlling the position of the mirror 4|. The electronic control devices will cause one of the clutch magnets to energize, thus coupling the shaft 35 for rotation in one direction. 'I'he manner in which this is effected will now be briefly set forth. The clutch magnets 25 and 25 are operated by gas filled tubes, designated A and B respectively in Fig. 19, of the type known as 2050 tubes. At the instant current is switched on and with mirror 4| out of liht reflecting position, there is no current flow in the plate circuits of the tubes and the cathodes and control grids of both tubes are at the same potential. Current therefor tends to flow through both tubes, but due to the unequal electrical characteristics of the tubes current is established in the plate circuit of one of the tubes before it is established in the plate circuit of the other tube. Assuming that such current flow is establishd in the plate circuit of tube A and thereby energizing magnet 25, such energizing circuit is traceable from negative side of source of 200 volts D. C., through a variable resistor C, cathode oi' tube A, plate of tube A, and magnet 25 to positive side of source.

The current flow through this circuit causes a voltage drop in the resistor C, whereby the potential control grid of tube B is made negative, thereby preventing establishment of current through this tube. Also, due to this action the plate of condenser D connected to magnet 25 is made negative and the plate of the condenser connected to magnet 25 is made positive. With magnet 25 energized. the gear 45 carrying cells 42 and light 43 rotates. 'I'he direction of the initial movement of rotation is immaterial. and it continues until the sensing assembly moves into the position for example, that shown in Fig. i9, wherein its relation to the mirror causes reiiection of light upon one of the cells 42 (the cell connected to tube B for the assumption made above). The photocell upon thus becoming conductive effects the controls of the electronic unit which will result in energization of the alternate clutch magnet 25.

Since tubes A and B are gas filled. they remain energized until their plate circuits are brought to a negative potential. Thus, the initial direction of rotation under control ci tube A continues until light falls upon the cell of tube B. Then tube B becomes conductive and current from 90 roltsource is applied to the cell and control grid of tube B, rendering this tube conductive and causing current to flow in its plate circuit to energize clutch magnet 26. Current flow in the plate circuit of tube B applies a negative bias to the control grid of tube A and incidentally causes condenser D to discharge. This causes the plate current in tube A to become negative, deenergizing magnet 25, and the negative bias now being applied to the control grid of tube A this tube cannot be fired.

With current now established in the plate circuit of tube B, magnet 26 is energized. The resulting shift in driving direction of the clutch causes the sensing'assembly to now move in the opposite-direction. If the compass needle 49 has not moved in the interim, the photocells and lamp wil1 turn substantially 10 (exaggerated in Fig. 19), at which time the reflected light beam will strike the opposite` or the alternate photocell. This causes operation of the electronic unit to bring about energization of the alternate clutch magnet, reversing the direction of rotation of the sensing assembly a second time to effect a reversion to the original direction of rotation.

In this manner as long as magnetic needle 40 remains motionless, the sensing assembly will continue to oscillate or hunt through an angle of approximately equally divided on either side of the true position of the needle, and the gearing from the drive motor is such that the oscillating will occur at a rate of about 150 reversals per minute. As soon as any change occurs in the position of the needle, the photocell control causes the sensing assembly to follow the needle until it is overtaken in its new position, after which the continuous hunting action resumes. Brieiiy, then, shaft 39 and the shaft 3|, which is geared to it, will move in one direction or the other to follow the direction of movement of the compass needle, and having reached such position will oscillate within the limits prescribed.

Referring now to Figs. 1 and 14, shaft 3| has a gear 6| thereon which through a train of gears generally designated 62 drives a rod 63, which in turn through bevel gear connection 64 drives a vertical rod 65, so that as the shaft 3| oscillates or turns the vertical rod 65 will go through the same motion. Secured to the upper end of this rod is a bifurcated lever 66 between whose separate arms is a pointer 61 normally restrained afgainst movement by a suitable friction spring 68. yThis pointer indicates the course of the vehicle and its position is read on a dial 69 suitably graduated in degrees. This dial is rotatable on shaft 65 and has integral therewith a gear 10, so that` through a train of meshing gears generally designated 1| the dial may be rotated by means of a knob 12. When magnetic north and true north coincide, the dial 69 is adjusted so that its north graduation is in line with a marker 13 scribed in a supporting plate. Where there is a variation between true and magnetic north, the angle of declination is entered into the device by manually rotating the dial 69 the appropriate angle with respect to line 13. In order to adjust for a west declination, the knob 12 is turned in such a direction that the zero or north mark of the dial 69 moves to the west the appropriate number of degrees, and for an east declination' it is rotated in theV opposite direction.

Referring to i4.. the knob 12 by means of which the declination adjustment is made carries a bevel gear 14 at its lower end (see also Fig. i5), which through a bevel gear 15 rotates a gear 16 meshing with gear teeth of the differential cage 11 upon wliish the pinions 33 and 34 are mounted. The ellect of rotating knob 12 is to also rotate the cage 11. Assuming the driven gear 35 of the differential to be stationary. rotation of the cage 11 will cause rotation of gear 32 and its shaft 3|, the amount of angular displacement being in accordance with the extent to whichV the knob 12 is turned. This relative rotation introduces the angle of declination into the integrating mechanism. This adjustment of the position of the shaft 3| is transmitted through the gearing 62 (Fig. 14) to the pointer 61, the direction of rotation of the various gears being such that, when the disk 69 moves in one direction, the pointer Will turn in the s'ame di'- rection.

After the adjustment for the angle of declination has been made, the pointer 61 will always extend in the direction in which the vehicle is moving and the bifurcated lever 66 will oscillate back and forth through a 10 angle in accompaniment with the oscillation of the compass sensing assembly. There is suiiicient clearance provided between the arms of lever 66 and pointer 61 so that, where the vehicle is moving along a straight line, the pointer will not be disturbed. Briefly, to make adjustment for a west declination, the knob 12 is turned so that the zero or N mark of the dial 69 moves the required number of degrees counterclockwise from the fixed mark 13. The pointer 61 is also moved counterclockwise the same amount, so that the reading of` the pointer on the dial is the magnetic bearing. For east declinations, the adjustment is, of course, in the opposite direction.

Integrating mechanism-Referring now to Figs. 1, 2 and 12, the main oscillating shaft 3| carries a gear 18 which meshes with gear 19 secured to a shaft 80, upon which is secured a worm 8| which in turn drives a worm wheel 82 (see also Fig, 11) which drives a vertical shaft 83.

' Thus, the shaft 83 also oscillates when the vethe course of the vehicle changes.

hicle is following a straight line and rotates when At the upper end of shaft 83 there is secured a so-called sine disk 84' and at the lower end is a similar socalled cosine disk designated 85. These two disks 84 and 85 resolve the direction of movement of the vehicle into two components. Disk 84 is associated with the north-south components and the disk 85 is assoclated with east-west components. Each disk carries a pivoted block designated 86 which are displaced 90 with respect to the two disks. The block 86 of disky 84 rides in a slotted member 81 which is provided with rollers 88 supported in a stationary track 89 (see also Fig. 2).

The block 86 of the lower disk 85 controls an exactly similar member designated 90 which also is provided with rollers 9| guided in a stationary track 95. Each of the members 81 and 98 has adjustabiy fastened thereto a rack, that for the north-south disk being designated 93 and the one for the east-west disk being designated 94. The rack 93 drives a gear 95 (see also Fig, 10). This gear 95 has sleeve connection 96 with a shield 91 (Fig. 12), wherein the configuration of the shield 91 is shown. Immediately adjacent to shield 91 is a fixed or stationary shield 98 with cut-out portions arranged so that, as shield 91 is rotated 2,421,eaa

under control oi the gear and rack connection from the north-south disk I4, a varying number of ratchet teeth in each o! a pair of ratchets 09 and (see Figs. 10 and 13) will be exposed for cooperation with sets of pawls |22 and |20.,

Shield 91 has a portion of smaller radius cut for approximately one-fourth oi' its circumference, the remainder of the shield being of larger radius as shown in Fig. 12. The stationary disk $8 has two sections of a radius equal to the smaller radius of disk 91 so that, when disk 91 is rotated to substantially 180 from the position shown in Fig. l2, the ratchet teeth exposed will be in a position diametrically opposite to that shown in Fig. l2.

Tracing the relative position of the parts, when the pointer 61 indicates the vehicle is traveling due north, the north-south disk 04 which is geared to the pointerthrough the connections traced will occupy a position, where the pivot Ablock 86 (Fig- 2) lies along the horizontal axis of the disk, 90 in a counterclockwise direction from the position shown in Fig. 2. Accordingly, the rack 93 will be in its farthest position toward the left and, when in such position, the low portion of the shield 91 (Fig. l2) will be in substantial alignment with the corresponding right hand low portion of the stationary shield 90, so that the maximum possible number oi' ratchet teeth 'are exposed. When the vehicle is headed south,

disk 84 will have the pin 86 in a position 90 in a clockwise direction from the position shown in Fig. 2 or 180 from the due north position. As a result, the shield $1 will have its low portion coinciding with the left hand low portion of shield 9|!V (Fig. l2) to expose the maximum number of ratchet teeth on that side of the stationary shield. Y

In any other position of the north-south disk 84, the disk 91 and shield 88 will jointly expose a lesser number of ratchet teeth. Thus, if thecourse of the vehicle is southeast or southwest, the teeth will be exposed as shown in Fig. 12, while if the vehicle is traveling northeast or northwest, the ratchet teeth will be exposed on the opposite side as indicated in Fig. 13. It is to be noted that, if the vehicle is traveling east or west, the low portion of shield 91 will coincide with one or the other of the high portions o1' shield 98, so that no ratchet teeth are exposed under such circumstances.

Through substantially identical mechanism the east-west disk 85 also effects the adjustment of a shield designated |0| (Fig. l0). connection is from rack 94 (Figs. 10 and 11) to gear |02, sleeve |03 to the shield |0|, adjacent to which there is a stationary shield |04 corresponding to the upper stationary shield 9B. I'hese two shields by their relative positions will expose a greater or lesser number of teeth in a pair of ratchets designated |05 and |06. The previously explained declination adjustment or pointer 01 is also made on the disks 84 and 05, through shaft 3| to which both pointer and disks are connected, so that the angle of exposed ratchet teeth will be in relation to true north.

Referring now to Fig. l0, a flexible cable |01 is driven from the vehicle at a rate proportional to the speed of the vehicle. Connected to the cable is a bevel gear |08 which drives a bevel gear I 09 on a vertical shaft 0, to which is secured a ratchet (see Fig. l2). The ratchet drives a spring pressed pawl ||2 pivoted on a disk H3, which disk is integral with a gear ||4 which through gearing generally designated Il! 'I'he driving drives a large gear ill. Means is provided for uncoupling this drive, which means constitutes a manually operated slide ||1 which, when moved toward the left as viewed in Fig. 10, will rock a pivoted plate Ill clockwise to bring l. conical ring H0 into engagement with a conical pin |20 in the pawl I|2 to cam the latter out of engagement with the ratchet III.

Referring now to Fig. 12, the gear ||0 which is at rest when the vehicle is not in motion and which rotates in accordance with the speed of the vehicle has pivoted thereon four pairs o! pawls on its upper surface and tour like pairs of pawls on its lower surface. Considering the pawls on the upper surface, the four pairs are exactly the same so that explanation of one pair will suillce for the others. What is known as the north pawl is designated |2I, 'while the other, the south pawl, is designated |22. They are pivoted at |22 and are spring urged against a pin |24 in a follower arm |25. As the gear ||0 rotates, the follower arm |20, which is suilicient in width to extend across both the shields l1 and 00, will ride onv the peripheries thereof (see Fig. 5) and the high portion of either of the shields will hold the arm in such position that its pin |24 will maintain both the pawls |2| an'd |22 out of engagement with the ratchets II and |00, the pawl |22 being in the plane o! ratchet 00 and the pawl |2| being in the plane of ratchet Ill.

Where there is coincidence of low portions of the two shields, the arm |25 will permit the pair oi' pawls to move toward their respective ratchets. Provision is made, however, so that the tw"o ratchets of the pair cannot at any time concurrently engage the related ratchets. For this purpose each pawl is provided with a tail lying in the plane of ilxed cams which are generally designated |28 (Fig. 12). 'I'hese cams are so positioned that the north pawi |2| is held in the position shown in Fig. 12 during the period that the pawl is moving through a sector, wherein ratchet teeth would be exposed if the direction or the vehicle were south or a component of its direction is south.

Similarly, as shown in Fig. 13, the south pawl |22 is held out of engagement with ratchet teeth as it passes through a sector in which teeth would be exposed as a result of the direction of the vehicles travel being north as one component. Thus, assuming, for example, -as in Fig. l2 the position of the shields 91 and 90 exposes a number of teeth, which represent that the vehicle is traveling in a direction of which south is a component, then as the gear III rotates, each pawl |22 will in turn drop into the first exposed tooth of the ratchet and drive the ratchet with gear H6 until the pawl is lifted out of engagement with the ratchet due to arm |25 riding on to the high portion of the ilxed shield Il. During such driving engagement, the north pawl |2| is held out by the lower of the cams |20. If the vehicle were tion, ratchet teeth would be exposed as in Fig. 13. wherein as gear ||6 rotates, the north pawl |2| will drop into engagement with the ilrst exposed tooth to drive the ratchet |00 until disengaged by the arm |25 riding up on the high DOrtion of the stationary shield 00.

During this period of engagement, the upper cam |26 will hold the south pawl |22 out of active position. It will be noted in Figs. 12 and 13 that the amount that either ratchet is advanced is proportional to the integral number of teeth of the ratchet. Thus, the movable shield may vary traveling in the opposite direc-- shield 91 receives this oscillation which on the shield itself approximates a ratchet tooth space. It was also explained that this oscillation is fairly rapid, being in the neighborhood of reversals per minute. Thus, where, for example, let us say 5/2 ratchet teeth are exposed, the ratchet `would be moved through five teeth as one pawl drives it and, as successive pawls drive it, the oscillation of the shield 91 would at times expose the teeth sumciently to drive six and at other times suiliciently to drive only four. The percentage of number of times that four, ve or six teeth are driven that will result over a period of time vis proportional to the percentages of the four, ve and six tooth space included in the total number of times the ratchet is driven.

Referring to Figs, 5 and 10, the underside of gear ||6 carries four pairs of pawls exactly similar to the pawls described on the upper side of the gear which cooperate'with the ratchets |05 and |06 in exactly the same manner, so that their operation need not be separately described. The pawls are indicated in Fig. 5 where the east pawl is designated |21 and the west pawl |28, while the common arm corresponding to arm |25 on the upper side is designated |29. Thus, the east ratchet |05 is driven an amount proportional to the easterly component of direction and the West ratchet |06 is driven an amount proportional to the westerly direction of movement.

Counter drive mechanisme-The movement of the four ratchets is transmitted through mechanism to a pencil or scriber to control the movement thereof for tracing the course of the vehicle on a suitable map. The component of movements is also transmitted to counters for separately registering and indicating the extent oi movement of the vehicle in the several directions as will now be described.

Referring specifically to Fig. 10, the north ratchet |00 is pinned to a vertical rod which has a gear |30 pinned to its upper end (see also Fig. 2). Gear |30 drives gear |3| and meshes with a gear |32 which in turn through gear |33 drives gear |34 Gear |34 drives gear |35 integral with one of the pair of bevel gears |36 for driving a shaft |31. IShaft |31 (Figs. 1 and 14) through gearing |30 drives a shaft |39 (see Fig. 18) which has worm and wheel connection |40 with a shaft |4|, which through gears |42 (Fig. 20a.) drives a counter of the well known Veeder type. Through gears |43 (Fig. 18) shaft |4| also drives a second counter in Aaxial alignment with the'lrst v counter. The second counter is driven directly, while the iirst is driven through an idler so that they advance in opposite directions, that is, when one counter advances additively, the other advances subtractively.

The two counters shown in Fig. 18 are designated north and south and, when the vehicle is moving in a northerly direction, the distance so traveled is entered into the'north counter while at the same time the distance is subtractively entered into the south counter. A shutter is provided in association with each counter which is shown in Fig. 20, where it is designated |44. A ilnger on the shutter cooperates with the cam |45 of the highest order wheel of the counter in such manner that, when a 9 is displayed in such order indicating that a complement is registered thereon, the shutter will move into position to cover the reading line of the counter. In other words, if the vehicle has moved a certain distance north from a. starting position, the south'counter will be covered and the north counter exposed for reading. If in the course of travel the vehicle arrives at a point south of its starting position, the counter will have been reversed so that the south counter now has a. positive reading and the north a complementary reading, in which case the shutter of the north counter will prevent reading thereof while the south counter will be exposed.

Referring back now to Fig. 10, the south ratchet 99 is integral with a gear |46 through a sleeve |41. 'I'his gear |46 (see Fig. 2) has direct driving connection to the gear |35, throlgh gear |34, and from here drives the shaft |31 to operate the counters but in a. reverse direction to that in which the counters are driven by the north ratchet |00. Directional arrows in Fig. 2 show the direction of rotation of the several gears and the shaft |31 when driven by the north ratchet through gear |30. In such case it will be noted that gear |34 rotates counterclockwise and urges the gear |46 in a clockwise direction, and that such gear is permitted to move in such direction since, if the vehicle is moving north, the south ratchet is freely rotatable. On the other hand, if the vehicle is moving south, the gear |46 will be positively driven in the counterclockwise direction, in which case the rotation of gear |34 will b'e reversed to in turn reverse the direction of rotation of shaft |31 and incidently of the counters. The north ratchet at such time will be free so that the 'back action through the gear train will not be obstructed.

Through an exactly similar system of gearing the east-west ratchets |05, |06 drive a second pair of counters indicated m Figs. 5 and 10, in the latter of which a gear |48 is integral with the east ratchet |05 and the gear |49 is integral with the west ratchet |06. The gear train is generally designated |50 and through it the cross-shaft |5| corresponding to the shaft |31 for the northsouth components is driven. This shaft |5| through gearing |50a (Fig. 14) drives a shaft |5|a. The shaft |5|a (Fig. 18) through worm and wheel connection |52 drives a shaft similar to shaft |4| -to operate a pair of counters designated east-west in Fig. 1 in the same manner. These counters also are provided with shutters |44 to register the distancetraveledin the designated directions from the starting point.

A total counter for indicating the total number of miles traveled is shown in Fig. 1, where it is designated |53. This counter is driven through a pair of bevel gears |54 which through a train of gearing |55 are driven from a shaft |56 (see also Fig. 2) wherein the extremity of this shaft has bevel gear connection |51 (see also Fig. 10) wthone of the gears of the train designated H5 which, as previously explained, is directly driven from the driving 'cable |01. The total counter |53 is thus directly Idriven from the driving motor or wheels of the vehicle and gives a direct-odometer indication of the total miles traveled.

Rcsettlng oi' the total counter |53 is, through bevel gearing |13 (Fig. 1) operated by a knob |14. Resetting of the component counter is effected by rotation of a gear |15 (Fig. 18) by means of a suitable handle. This gear |15 has driving connection for concurrently rotating the axle shafts of the four counters. Prior to rotating gear |15 a lever |16 is manually rocked clockwise, as viewed in Fig. 18 about its pivot |11 whereby its upper end will draw the counter axle shafts |19 to the right against springs |80. This action, in the usual manner, couples the counter wheels, internally, to the shaft |19 so that as the shaft is then rotated the wheels will be reset to zero.

Transmission mechanism-Referring now to Fig. 2, the gear |32 as explained is driven counterclockwise when the vehicle is moving north and clockwise when the vehicle is moving south, and the corresponding gear of the chain |50 (Fig. likewise rotates in one direction for easterly movement and in the opposite direction for westerly movement. Integral with the gear |32 is a bevel gear |58 and the lower gear of the chain |50 is integral with a similar bevel gear |59, which two bevel gears respectively mesh with bevels |60 and |6|. Bevel |60 drives a gear |63 and bevel |6| drives a gear |62, which two gears are concentrically mounted on the same axis and each drives separate mechanism, one for controlling the movement of a pencil in one direction and the other for moving the pencil in the transverse direction.

Considering rst the mechanism driven by the gear |62, this gear through a sleeve |64 drives a gear |65 (see Fig. 4) which through intermediate gearing designated |66 drives a large gear |61, the direction of drive being such that, when the vehicle is moving in a Westerly direction, the

direction of rotation is reversed from that when' the movement of the vehicle is easterly. Integral With gear |65 is a cam |68 which cooperates with a follower |69 integral with a circular shield |10 to oscillate the'shield about a normally stationary sleeve or tube |1| (see Fig. 6). AImmediately adjacent the shield is a settable shield |12 coniigured as shown in Fig. 4 which is secured to sleeve |1|. Both shields have low and high portions related so that with the parts in the position shown in Fig. 4, a maximum low portion of the two shields is in coincidence. As cam |68 rotates in either direction, this amount of low opening will gradually decrease and then increase again due to the oscillation of shield |10.

Disposed in opposite openings |8| in gear |61 and lying in the plane of the gear are arms |82 plvoted at |83 to a suitable bracket arm secured to the gear. Each arm has a pin |84 extending across the shields |10 and |12 in one direction (see Fig. 6) and extending beneath the free ends of a pair of pawls |85, |86 in the opposite direction. These pawls are pivoted on gear |61 so that they rotate therewith in a clockwise direction as viewed in Fig. 8 when the vehicle is moving in a westerly direction and in a counterclockwise direction when the vehicle is moving in an easterly direction.

In the plane of pawls |86 is a ratchet |88 and in the plane of pawls |65 is a ratchet |89, the two ratchets being integral and with their teeth facing in opposite directions so that they will be driven together in the direction of rotation of gear |61. A gear |90 (Figs. 2 and 6) is also integral with the ratchets and turns therewith. If the pawls were arranged to be in constant engagement with their ratchets the gear |90 would be driven at all times for east-west movement, in direct proportion to the distance traveled.

In order to render the device suitable in connection with various map scales, the shields |10, |12 are provided to control the pawls |85, |86 so that a greater or lesser part of the angular distance through which gear |61 travels is transmitted to gear |90. Thus, with the shields |10, |12 adjusted for maximum coincidence of their low portions, pin |84 of one pair of pawls lowers into the cuts in the shields and allows the pawls to drive the ratchets for 180 degrees and then the opposite set drives the ratchets, the two sets thus alternating in their driving action, while shield |10 oscillates to produce an averaging effect in the same manner as explained for the integrating ratchet drive.

The manner in which shield |12 is adjusted can be seen from Fig. 6 where the shield is shown as having its sleeve |1| pinned to shaft |9|. Turning of knob |92, which is integral with the enlarged head |93 of the shaft |9I, will position shield |12. A vernier knob |94 is provided, which when turned will turn a spring pressed rod |95 whose conical surface will rotate balls |96 within head |93 against a xed race |91 and thereby obtain slight rotation of the shaft |9|.

Attached to knob |92 is a calibrated dial |98 (Figs. 3 and 9) with which a pointer |99 cooperates to indicate the map scale for which the shield is set. This pointer is carried by a horizontally positionable shield 20| provided with a window 200 through which only one of the four circum- 'ferentially arranged sets of graduations on the dial |98 may be read. These four arcs of graduations represent four major scale ranges for which f the device may be adjusted and these ranges vary :in the ratio of l to 2.5 between successive ranges. 'Through transmission gearing yet to be described a scale range is selected and shield |99 accordf ingly adjusted to position the window 200 in line with the selected range. Then the dial |98 is rotated to bring the desired scale within the selected range into alignment with the pointer |99.

Through mechanism exactly similar to that just described, the north-south integrated movement applied to gear |58 (Fig. 5) and gear |63 is transmitted to a gear |a (Fig. 6) which corresponds to gear |90. The detailed description of these connections may thus be omitted and their identity is indicated by designating'the parts with the same reference characters as applied to the east-west mechanism followed by the suilix a.

Referring to Fig. 3, the shield 20| has a pin 203 which cooperates with a cam 204 secured to a knob 205. A spring 206`urges the shield toward the left and as knob 205 is adjusted to align its pointer with one of the four scale range numerals shown, shield 20| will shift to place its window 200 in the appropriate position for reading the related dial graduations.

The shaft 201 of knob 205 (Figs. 4 and 7) has secured thereto a disk 208 having a V notch 209 in each face into which spring pressed, pivoted clutch levers 2|0 enter when the notches are aligned therewith. Positioned circumferentialiy around the disk 208 are four sets or pairs of levers 2|0, one pair for each of the four positions of the disk so that any pair may be selected for alignment with the single set of V notches 209.

Each lever 2|0 when rocked into a notch slides a gear tooth clutch element 2| 2| la, 2|4, 2|4a,

215, 215a, 216 or 218a into position for driving engagement by the gear 190 or 190a as may be traced in Fig. 2. In this ligure the levers 210 farthest to the right are rocked and have eiected a coupling action whereby the rotation of gear 190 is transmitted through idler 212, gear 213, gear 211, gear 214, gear 215, to gear 21B which is keyed to shaft 224. This shaft is releasably coupled to a bevel gear 211, as will be explained, and through gear 211 the east-west movement is given to the pencil or marker.

Through the second of the pair of clutches engaged, the north-south gear 198a drives idler gear 213a, gear 211a, to gear 214g, which is keyed to shaft 218. This shaft is releasably coupled to a bevel gear 219 to drive the pencil in northsouth direction. Referring to Fig. '1 shaft 218 has a beveled disk 220 pinned to its extremity, which normally bears against a beveled surface 221 within knob 222 under the influence of a spring 223. The knob 222 has sliding key connection with bevel gear 219 so that as shaft 218 is rotated, disk 220 drives knob 22| and it in turn drives bevel gear 219. By pressing knob 222 toward the right to the position in which it is shown in Fig. 7. the drive is disconnected so that if knob 222 is now turned it will turn bevel 219 independently of the gear connections. This is done when the pencil is initially adjusted at a selected starting position.

The east-west shaft 224 is coupled to its bevel gear 211 in an exactly similar manner through the setting knob 225 (Fig. 2)

Accordingly the bevel gears 219 and 211 are rotated in one direction or the other in accordance with the direction of movement of -the vehicle and an amount proportional to the distance traveled in such direction, the proportion depending upon the ratio preselected by the set-- ting of knobs 192 and 205.

Referring to Fig. 2, bevel gear 219, drives a rod 22B through a bevel gear 221 and bevel gear 211 drives a rod 228 through a bevel gear 229. In Figs. 3 and 22 rod 226 through a pair of gears 230 drives the north-south lead screw 23.1, and rod 228 through gear 232 drives a vertical rod 233 which in turn through gears 234 drives a shaft 235. Referring to Figs. 21 and 22, shaft 235 is splined and has slidable thereon a bevel gear 23S which through bevel gear 23-1 drives the east-west lead screw 238 which is mounted in a carriage 239.

Supported on carriage 239 and threaded for movement by the screw 238 is the pencil holder 240 Which is pivoted at 241 (Fig. 24). Pencil 242 is supported in the holder in a suitable manner and bears upon the map or chart 243. Pressure applied to a linger piece 244 will rock a latch 245 about pivot 246 and rock the holder 240 clockwise about its pivot 241 to a position where latch engages the upper notch 241 in which the holder is detented and disengaged from screw 238. In such position the holder may be moved freely along the screw 238 for initial positioning, or the pencil rendered inoperative. Pressure upon nger piece 24'8 will rock the holder back into the position of Fig. 24,

The carriage 239 is provided with rollers 249 guided in tracks 250. Secured to the underside of the carriage is a block 251 (Fig. 23) in which is a spring pressed nut 252 through which screw 231 moves the carriage along the screw. Pressure against nger 253 in a clockwise direction as viewed in Fig. 23 will rock member 254 about pivot 255 and through pin and slot connection 256 the nut 252 will be raised out of engagement 14 with the screw 231, so that the carriage may be moved freely.

Extending across the carriage is a rod 251 having a gear 258 at each end which mesh with stationary racks 258 and serve to maintain the carriage in proper parallel alignment as it is advanced. Pointers 260 and 261 on the pencil holder and carriage respectively cooperate with suitable scales to aid in locating the pencil.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a single modification, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention therefore to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. In a navigating instrument for a vehicle, a set of four coaxial ratchets, one for each of the cardinal points of the compass, a gear coaxial with said ratchets, a, driving pawl for each ratchet carried by said gear, means for operating said gear and pawls continuously in the same direction in accordance with the speed of the vehicle, shielding mechanism coaxial with said ratchets for controlling the extent of engagement of the related ratchets and pawls, and compass controlled -means for selectively positioning said shielding mechanism and for oscillating the said shielding mechanism within a predetermined angle at its selected position to enable rotation of the ratchet or ratchets related to the direction of movement of the vehicle and to control the extent of movement of each 2. In a navigating instrument for a vehicle, a ratchet wheel related to a point of the compass, a driving pawl therefor driven continuously in accordance with the speed of the vehicle, a shield for controlling the extent of engagement of the pawl and ratchet, compass controlled means for adjusting said shield to expose a predetermined portion of the ratchet to the pawl for a given compass direction, and eiective upon initial adjustment of the shield for altering its adjustment to repeatedly expose a greater and then a lesser portion of the ratchet than said predetermined portion, wnereby the pawls engagement will vary to produce an average ratchet movement for a given direction over al period of time.

3. In a navigating instrument for a vehicle, a pair of concentric ratchet wheels, a disk coaxial therewith, a pair of pawls carried by said disk, one pawl for each ratchet, said disk being driven continuously in accordance with the speed of the vehicle, a fixed shield configured to expose a portion of the periphery of the ratchets for engagement by the pawls at two diametrically opposite positions, a positionable shield settable to render the fixed shield eilective at either or neither of its ratchet exposing positions, means for setting said positionable shield, and further means for causing the pawls to engage the exposed periphery of their related ratchets at only said diamctrically opposite positions of exposure, whereby only one of the ratchets will be driven.

4. In a navigating instrument for a vehicle, a toothed ratchet wheel, a driving pawl cooperating therewith, means for continuously driving said pawl in accordance with the speed of the vehicle, compass controlled means for rendering said wheel responsive to the action of said pawl through a predetermined amplitude for a given direction of the vehicle, and means for alternately and repeatedly increasing and decreasing said amplitude.

5. In a navigating instrument for a vehicle, a toothed ratchet wheel, a continuously moving driving pawl, a pair of shields for controlling the extent of driving engagement between the pawl and ratchet, compass controlled means for adjusting the relative positions of said shields for a given direction of the vehicle to cause the pawl to drive said ratchet an integral number of teeth, and means for repeatedly adjusting said shields to cause the pawl to drive the ratchet alternately said number of integral teeth plus and minus a fractional tooth space.

6. In a navigating instrument for a vehicle, a toothed ratchet wheel, a constantly driving pawl, a shield mechanism for effecting coupling and uncoupling of the pawl and ratchet and compass controlled means for repeatedly adjusting said shield mechanism for agiven direction to render the pawl effective to drive the ratchet over a predetermined amplitude range, whereby an average extent of drive will be effective over a given period of time.

7. In a navigating instrument for vehicles having integrating mechanism controlled by distance and directional devices, the combination with a shaft rotated by said integrating mechanism at a speed proportional to the speed of the vehicle and for a period proportional to the component of the vehicles direction, an element driven by said shaft, and connections between the shaft and said elementl comprising a ratchet geared to the element, a pawl driven by the shaft, and camming mechanism also driven by the shaft for controlling the period of engagement of said pawl and ratchet.

8. The invention set forth in claim 7, in which manually settable camming means is provided to variably limit the period of pawl and ratchet engagement, whereby the element will be driven at a variable ratio.

9. In a navigating instrument for vehicles having integrating mechanism controlled by distance and directional devices, the combination of a shaft rotated by said integrating mechanism at a. speed proportional to the speed of the vehicle in the direction of one of the points of the compass, a ratchet, a driving pawl engageable with the ratchet and'driven by said shaft, a. settable shield mechanism for controlling the period of engagement o! the pawl and ratchet, means controlled by the shaft for repeatedly varying the setting of said shield mechanism over a predetermined amplitude to effect an averaging driving connection between the pawl and ratchet, and an element driven by said ratchet.

10. The invention set forth in claim 9, in which manually adjustable means is provided to select the extent to which the pawl will drive the ratchet, said averaging means being eective in the same manner for each setting of said adjustable means.

11. The invention set forth in claim 9, in which a gear train is provided, said gear train having an input member driven by the ratchet and an output member driving the element, and means for selectively controlling the driving ratio from the output member to the input member, said ratios varying in a geometric sequence.

CLAIR D. LAKE. GEORGE F. DALY.

REFEBEN CES CITED The following references are of record in the file of this patent:

UNITED STATES PA'I'ENTS Number Name Date 1,592,553 Brewerton July 13, 1926 1,621,394 Bertin Mar. 15, 1927 1,873,126 Hugershoil' Aug. 23, 1932 1,985,265 Smith Dec. 25, 1934 2,309,790 Ross Feb. 2, 1943 807,996 Beede Dec. 19, 1905 1,830,004 Skoverski Nov. 3, 1931 1,834,209 Harper Dec. 1, 1931 1,992,252 Stoecklin Feb. 26, 1935 1,101,128 Jensen et al June 23, 1914 1,702,403 Holmes Feb. 19, 1929 1,704,250 Holmes Mar. 5, 1929 1,854,391 Avery Apr. 19, 1932 1,953,894 Crouse Apr. 3, 1934 1,963,457 Avery June 19, 1934 2,022,275 Davis Nov. 26, 1935 2,109,283 Boykow Feb. 22, 1938 2,028,028 'Iyler Jan. 14, 1936 1,941,963 Wise Jan. 2, 1934 FOREIGN PATENTS Number Country Date 381,230 Great Britain Oct. 3, 1932 729,640 France May 2, 1932 

